Datasheet

5
LT1738
1738fa
SHDN Pin Hysteresis Current vs
Temperature V
IN
Current vs Temperature
CS Pin to V
C
Pin Transfer
Function
Slope Compensation
Gate Drive High Voltage vs
Temperature
Gate Drive Low Voltage vs
Temperature
Gate Drive Undervoltage Lockout
Voltage vs Temperature
V5 Voltage vs Load Current
TYPICAL PERFOR A CE CHARACTERISTICS
UW
TEMPERATURE (°C)
–50 –25 0 25 50 75 100 125 150
SHDN PIN CURRENT (µA)
1738 G09
27
25
23
21
19
17
15
CS PIN VOLTAGE (mV)
0
20 40 60 80 100 120
V
C
PIN VOLTAGE (V)
1738 G11
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
T
A
= 25°C
DUTY CYCLE (%)
0
20 40 60 80 100
PERCENT OF MAX CS VOLTAGE
1738 G12
110
100
90
80
70
60
50
V
C
PIN = 0.9V
T
A
= 25°C
TEMPERATURE (°C)
–50 –25 0 25 50 75 100 125 150
GATE DRIVE A/B PIN VOLTAGE (V)
1738 G13
10.7
10.6
10.5
10.4
10.3
10.2
10.1
10.0
9.90
9.80
9.70
6.5
6.4
6.3
6.2
6.1
6.0
5.9
5.8
5.7
5.6
5.5
GCL = 12V
GCL = 6V
V
IN
= 12V
NO LOAD
TEMPERATURE (°C)
–50 –25 0 25 50 75 100 125 150
GATE DRIVE A/B PIN VOLTAGE (V)
1738 G14
0.50
0.45
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0
V
IN
= 12V
NO LOAD
TEMPERATURE (°C)
–50 –25 0 25 50 75 100 125 150
V
IN
PIN VOLTAGE (V)
1738 G15
7.3
7.2
7.1
7.0
6.9
6.8
6.7
6.6
6.5
6.4
6.3
GCL = 6V
TEMPERATURE (°C)
–50 –25 0 25 50 75 100 125 150
SS PIN CURRENT (µA)
1738 G16
9.5
9.3
9.1
8.9
8.7
8.5
8.3
8.1
7.9
7.7
7.5
SS VOLTAGE = 0.9V
LOAD CURRENT (mA)
–15
–10 –5 0 51015
V5 PIN VOLTAGE (V)
1738 G17
5.08
5.06
5.04
5.02
5.00
4.98
4.96
T = 125°C
T = 25°C
T = –40°C
Soft-Start Current vs Temperature
TEMPERATURE (°C)
–50 –25 25 75 125
V
IN
CURRENT (mA)
150
1738 G10
0
50
100
18
17
16
15
14
13
12
11
10
V
IN
= 12 R
VSL
, R
CSL
= 4.85k
V
IN
= 20 R
VSL
, R
CSL
= 17k
V
IN
= 12 R
VSL
, R
CSL
= 17k
USING LOAD OF FIGURE 1A
f
OSC
= 120kHz